On October 15, 2025, F5 disclosed that the company learned on August 9, 2025 “that a highly sophisticated nation-state threat actor had gained unauthorized access to certain [F5] systems.” F5 further revealed that “[d]uring the course of its investigation, [F5] determined that the threat actor maintained long-term, persistent access to certain F5 systems, including the BIG-IP product development environment and engineering knowledge management platform,” and that “[t]hrough this access, certain files were exfiltrated, some of which contained certain portions of the Company’s BIG-IP source code and information about undisclosed vulnerabilities that it was working on in BIG-IP.”
On this news, the price of F5’s stock fell over 10%, from a close of $330.75 on October 15, 2025, to close at $295.35 on October 16, 2025.
If you have any questions or would like to discuss this investigation, please contact Kessler Topaz Meltzer & Check, LLP: Jonathan Naji, Esq. (484) 270-1453 or via e-mail at info@ktmc.com.